Today, 4 February 2012 is Bhishma Dwadasi. Bhishma Dwadashi is an auspicious Dwadasi vrata observed on Shukla Paksha dwadasi in Magh month. It marks the end of Bhishma Panchak Vrata which begins on Bhishma Ashtami. Devotees who have started their Ekadashi vrata would break their fast on Bhishma Dwadashi by performing special puja to Lord Vishnu.
Dwadashi begins at 4.57 am on 4 February and ends at 5.38 am on 5 February 2012. Reciting Vishnu Sahasranama stotram and performing Vishnu puja are the best rituals to observe on Bhishma dwadasi.